1. Accounting is piss easy. If you have common sense and can add or subtract, you should be fine.
Year 11 is the harder part and worth 70% of your whole HSC.
During this time, I studied a week before exams
Year 12 is basically open book for everything. I didnt touch exercises before going into exams, so basically when i did tests, it would be the first time that i see any content. I still did fine.
2. Accounting scales quite well for a TVET subject and something so easy. However the better you do, the better it scales. To give you an idea, it scales better than bio/ancient/legal/business etc. It scales just below phys/chem/eng.
3. Besides afternoon classes when everyone else went home I loved it. Not so much the content itself but how easy it is to do well. If you are thinking about it, you should def do it, You can always drop it later!